This invention relates to racquets.
A typical racquet comprises an approximately oval frame, usually of wood or extruded aluminum, having a plurality of holes extending substantially radially therethrough, the stringing of the racquet being directly secured to the frame by passing individual strings thereof through the holes. Typically, a given string is passed outwardly through a respective hole in the frame and then inwardly through an adjacent hole.
However, such a racquet suffers from a number of disadvantages. For example, parts of the stringing are at least partly exposed at the radially outer surface of the frame (i.e., between adjacent holes in the frame), and are thus subject to damage as a result of impacts, e.g., with the ground. Also, the strings tend to fret against the frame, especially where they pass over the edges of the radially outer ends of the holes in the frame, this fretting eventually leading to breakage of the strings. Additionally, manufacturing costs are increased by the necessity for drilling and deburring the holes, and providing and fitting grommets in the holes, all of which operations can be labor intensive. Most significantly, the holes in the frame tend to set up stress concentrations so that when the frame is severly stressed, it almost invariably breaks in the region of a hole.
It has already been proposed, in my United Kingdom Patent Application No. 8200722 (Publication No. 2,094,643, published on Sept. 22, 1982), which corresponds to the above-mentioned U.S. Application Ser. No. 577,330, to alleviate the above-mentioned disadvantages by providing a racquet in which the frame has a groove extending around the greater part of its internal periphery. The stringing of this racquet is secured to the frame by means of a one-piece sinuous string-securing member made from a suitably bent length of wire. This member is held in the groove by making the width of the portions of the wire disposed in the groove exceed the width of the mouth of the groove by deforming them or by crimping the mouth of the groove.
This proposal, although it does indeed alleviate the aforementioned disadvantages and provides excellent racquets, nevertheless suffers from a number of production drawbacks. In particular, the deforming and crimping steps can be rather time consuming, and holding the wire string-securing member in the groove during the crimping operation presents some difficulty. Additionally, the frames of racquets in accordance with the proposal are usually made from extruded aluminium, often with highly decorative finishes which are produced, for example, by anodizing. These finishes can be adversely affected by the crimping operation, while the actual deformation produced by the crimping operation can of itself detract somewhat from the pleasing aesthetic appearance of the racquet.